题目描述

blablabla

样例

blablabla

算法1

Java 代码

import java.io.*;
import java.util.*;

public class Main {

    static class UFind {
        int[] father; 
        int[] d;
        UFind(int n){
            father = new int[n+1];
            d = new int[n+1];
            for(int i = 1; i <= n; i++){
                father[i] = i;
            }
        }

        public int find(int x) { 
            if(father[x] != x){
                int u = find(father[x]);
                d[x] += d[father[x]];
                father[x] = u;
            }
            return father[x];
        }

        public void union(int p, int q) { 
            int fp = find(p);
            int fq = find(q);
            if(fp != fq){
                father[fp] = fq;
            }
        }

        public boolean D1(int x,int y){
            int fx = find(x);
            int fy = find(y);
            // 判断同类
            if (fx == fy){
                if ((d[x] - d[y]) % 3 == 0){
                    return true;
                }else{
                    return false;
                }
            }
            father[fx] = fy;
            d[fx] = d[y] - d[x];
            return true;
        }

        public boolean D2(int x,int y){
            int fx = find(x);
            int fy = find(y);
            if (fx == fy){
                if ((d[x] - d[y] - 1) % 3 == 0){
                    return true;
                }else{
                    return false;
                }
            }
            father[fx] = fy;
            d[fx] = d[y] - d[x]+1;
            return true;
        }

    }

    static BufferedReader read = new BufferedReader(new InputStreamReader(System.in));
    static BufferedWriter log  = new BufferedWriter(new OutputStreamWriter(System.out));
    public static void main(String[] args) throws Exception {
        String[] s = read.readLine().split(" ");
        int n = Integer.valueOf(s[0]);
        int m = Integer.valueOf(s[1]);
        UFind uf = new UFind(n);
        int res = 0;
        for(int i = 0; i < m; i++){
            s = read.readLine().split(" ");
            int d = Integer.valueOf(s[0]);
            int f1 = Integer.valueOf(s[1]);
            int f2 = Integer.valueOf(s[2]);
            if(f1 > n || f2 > n){
                res++;
                continue;
            }else if(d == 2 && f1 == f2) {
                res++;
                continue;
            }else{
                if (d == 1){
                    if (!uf.D1(f1, f2)){
                        res++;
                        continue;
                    }
                }else if(d == 2){
                    if (!uf.D2(f1, f2)){
                        res++;
                        continue;
                    }
                }
            }
        }
        log.write(res + "\n");
        log.flush();
    }
}